1. Field of the Invention
The present invention relates to a vehicle bumper structure, and particularly relates to a vehicle bumper structure for an automobile or the like which is provided with an energy-absorbing member.
2. Description of the Related Art
Secondary structures at bumper structures of vehicles such as automobiles and the like have been known heretofore. There is a structure in which left and right side members extend in a front-rear direction of a vehicle, a bumper reinforcement which extends in a vehicle width direction spans between front ends of the left and right side members, a bumper cover is provided forward of this bumper reinforcement, and an extension member is fixed at a front wall of the bumper reinforcement and extends close to a rear face of the bumper cover. Thus, directly after a collision, an impact load is transmitted from the bumper cover through the extension member to the bumper reinforcement, and is further transmitted to the left and right side members. (See, for example, Japanese Patent Application Laid-Open (JP-A) No. 2000-001150.)
However, with this vehicle bumper structure, when there is a frontal collision, a load that is generated is concentrated at a vehicle width direction central portion of the bumper reinforcement, and buckles the bumper reinforcement toward the rear of the vehicle. Consequently, loads in the left-right direction are generated at the front ends of the left and right side members. As a result, buckling modes of the left and right side members vary in accordance with the collision speed, and a speed dependency of loads generated in the side members is reduced. Therefore, if an acceleration sensor for operation of an airbag is provided at a rear end of a side member, that airbag cannot be operated in optimum conditions. Furthermore, because the extension member is made of metal, costs for repairing an extension member when it has been deformed by a low-speed collision are high.